Shotgun feed mechanism for sawmills



W.'F. CLARK.

SHOTGIUN FEED MECHANISM FOR SAWMILLS.

APPLICATION FILED IIIIIY24l 1919.

Patented Mar. 1 5, 1921.

2 SHEETS-SHEET l.

E; A o N E aia I CQ mXgr 3 t S@ Q \N N\ W. F. CLARK.

sHoTGuN FEED MEGHANISM Fon sAwMl'LLS.

APPL'ICATION FILED MAY 24, i919v mmm@ Mar. 15, w23.

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2 SHEETS-SHEET 2.

UNITED STATES WILLIAM F. CLARK-, OF

LAUREL, MISSISSIPPI.

. SHOTGUN FEED MECHANISM FOR SAWMILLVS.

Application f1ed`May 24,

To all 'whom t may concern.'

Be it known that I, VILLIAM F. CLARK, a citizenof the UnitedStates of America, residing at Laurel, in the county of Jones and State of Mississippi, have invented new and useful Improvements in Shotgun Feed Mechanism for Sawmills, of which the following is a specification.

The object of the invention is to provide simple and efficient means whereby the intermediate support of the piston rod by which the carriage is actuated,or by which motion is communicated to the carriage, may be controlled in its operation, that is to say in its movements to and from operative relation with the piston rod, by the carriage itself, so as to insure a proper and invariably accurate timing of the movements o f the elements of the mill regardless of the rapidity7 of movement of the carriage either in its forward or return strokes,and regardless of the relative speeds of said forward and return strokes.

Further objects and advantages of the invention will appear in the following description of a preferred.embodiment thereof` it being obvious that changes in form and proportion may be resorted to within the scope of the v.appended claims without departing from the principles involved. Y

In the drawings:

Figure 1 is a plan view of a mechanism embodying the invention applied in the operative position toa saw mill carriage and railed apparatus. v

Fig. 2 isa front elevation of same.`

Fig. 3 is adetail sectional view taken in the plane ofthe piston rod and the support for the same, the latter being shown in its operative relation with the former.

Fig. 4 is a vertical sectional view taken in a plane at right angles to that of Fig. 3 as shown by the line 4 4 of said figure.

Fig. 5 is a detail sectional view of the return end of the piston guide or cylinder to show therein an ordinary form of yielding buffer or cushion to receive the impact of the piston and the parts connected therewith upon the return stroke of the carriage.

In the illustrated embodiment of the apparatus the carriage 10 is mounted in the usual way upon the supporting guides or tracks 11 upheld by a suitable framework indicated at 12, said carriage being connected in the ordinary or any preferred manner with a piston rod 13 provided with a pis- 1919. serial No. 299,619. v

Specicaton of Letters Patent. v Pattgd `lwar, f5,

ton head V14v operating in the tubularv guide or cylinder 15.

Disposedffor axial movement diametrically of the pistn guide or cylinder atan intermediate point lthereof is a reciprocating piston supporting pin lmounted preferably in an elongated cylindrical guide 17 having a packing box 18 and provided with a cross head 19 exposed to Ythe action of retraction springs'20, the tension of which is directed to the withdrawal of the supporting pin fromterminal contactzwith the piston rod 13, said pin being providedV at its upper terminal with a concaved seat 21 in whichthe piston rod is adapted to rest in the course of the forward movement of the carriage while a saw cutis being made.

' The means for actuating the supporting` pin to move it to its normalor active position `consists of a plunger 22 operating in a cylinder 23 and having a stem 24 connected by a link 25 with said supporting pin, the pivotal joints 26 and 27 at the extremities of the link and` by which connection is made respectively with the supporting pin and the plunger stem aredisposed axiallyat right angles fromeach other so that slight vibrations of either the cylinder or the means carryingY the pistonrod will not cause the binding ofthe supporting pin 0r the plunger in their' respective guides.

Any suitable, preferably expansive motive agents may be employed as the means for actuating'the plunger22 to advance the supporting pin 16 toits operative relation with the piston or carriage operating rod 13, as for example, steam admittedthrough a supply vpipe 28, valve 29 containing, for instancea slide valve chest 30 controlling the cylinderports 3l and 32and the Vstem 33 of said controlling valve is connected with a tappet arm 34e-having vitsv Contact ,terminal preferably provided with an anti-'friction roll 35, arranged for Contact with a cam 36 on the carriage. Any suitable and practical means for communicating motion from the tappet arm to the valve stem 33 may be employed such as bell crank levers 37 and 38 and the connecting rod 39 arranged in such relations that when the tappet arm is act-uated by the camA 36 the valve 30 will open communication between the valve chest andv the lower end of the cylinder 23 so as to elevate the plunger 22 and thus bring the upper end of the supporting pin in supporting relation with the piston rod 13, the depressed or operative position of said tappet arm being maintained during the continuous movement of the carriage by means of a guide 40 forming an extension of said cam and extending parallel with the path of movement of the carriage.

Any suitable cushion or buffer means may be employed at the end ofthe piston guide 15 `to receive the impactof the piston upon the return movement of the carriage, such as the spring 41 indicated in detail in Fig.- 5.

Upon the return movementof the carriage andthe consequentrelease `of the tappet and trip arm 3&1, the position of valve 30 will be reversed to permit the exhaust of steam from the lower endof the cylinder 23 and the downward movement of the plunger 22 may be insured by directing steam into the upper end of the cylinder through the port 32. Under any circumstances the expansion ofthe springs serves to withdraw the i supporting pin fromengagement with the piston rod 13, and, should upper extremity of said pin project into the guide 13, its

complete repression will be effected by the Contact therewith of the cam face 36 on the front end of the piston head 14. l

From the "foregoing description Vit will be obvious that during the relatively slow forward movement of the carriage the intermediate portion of the piston rod 13 will be supported to prevent sagging and hence disalinement and tendency to interfere with the freedom of movement of the piston` head 14:, whereas the withdrawal of the supporting pin to avoid thecontaet therewith of the piston-head will be effected under conditions dependent solely upon the po-` sition of the carriage, the cam 36 being duplicated at the extremities ofthe carriage so that the supporting pin is only in operative relation with the piston rod when, owing to the position of the carriage, the sagging of the intermediate portion of the rod is likelyto cause trouble in the operation of the mechanism.

The invention having been described, what is claimed as new and useful is:

1; Means for intermediately supporting the piston rod of asaw mill carriage having a supporting pin movable axially in diametriout of operative engagement with said rod,

yielding means for retracting said-pin, a plunger for communicating movement of the supporting pin to its operative position, means for applyingV fluid' pressure to said plunger, and devices for controlling the application of said fluid pressure including a vtrip arm and a carriage supporting cam for actuating said arm. y

3` Means for intermediately supporting the piston rod of a saw mill carriage having a reciprocable supporting pin for movement toward and V from said piston rod and provided with a terminal seat for engaging the same, yielding means for retracting said pin, a plunger operating in a fluid pressure cylinder, a universal connection between said plunger and the supporting pin, and means for controlling the application `of fluid pressure of said plunger, said means including an actuating device carried by the saw mill carriage.

l. Means for intermediately supporting the piston rod of a saw mill carriage having a supporting pin axially movable in diametrical relation to said piston rod, a plunger having a universal connection with said supporting pin and arranged for operation in a fluid Vpressure cylinder, valve mechanism for controlling the fluid pressure to saidcylinder, a trip `arm connected with said valve mechanism, and a cam actuated by the saw mill carriage for operating said trip arm, the saw mill piston head having a cam for displacing the supporting terminal of said supporting pin on the return movement of the carriage.

In testimony whereof he aflixes his signature. i

VILLIAM F.v CLARK. 

